Nonflammable solvent



Patented Sept. 2, 1941 NONFLAMMIABLE SOLVENT Johan 'Bjorksten, Chicago, Ill.,-assignor to Ditto,

Incorporated, Chicago,

West Virginia No Drawing.

III., a. corporation of Application December 5, 1938,

Serial No. 244,055

4 Claims.

The, invention relates to solvents and more particularly to solvents for use in direct wet process duplication.

In direct wet process duplication a design is formed in mirror reverse on a master copy by any suitable means. The master sheet is moistened with a solvent for the dyestufi' of the design so as to dissolve a thin surface layer of the dye impressions on the master sheet. Copy sheets are then contacted with the moistened master sheet, so that the thin layer of dissolved dye on the master impression is transferred to the copy sheets. In most instances alcohol soluble dye stufis have been used to form the design of the master copy, and consequently the moistening solvent usedin the process has been ethyl alcohol, methyl alcohol or a mixture of the two.

Because of the flammability of these materials it has not hitherto been practical to employ electrically driven machines incarrying out the direct wet process duplication method, because of the danger of sparks igniting the alcohol. wet process duplication method has therefore been limited to hand driven equipment, which naturally retarded the expansion of this otherwise meritorious process.

One-embodiment of this invention is a mixture of mono-fluoro tri-chloro methane and any of the flammable organic solvents suitable for dissolving duplicating dye stuif used in direct process duplicating methods.

I It has been discovered that as little as 3% of mono-fluoro tri-chloro methane added to a flammable solvent for duplicating dyes is suflicient to substantially reduce the flammability of the solvent. The exact amount of mono fluoro trichloro methane necessary to render a solvent suitable for use in conjunction with electrically driven machines naturally depends on the other ingredients of the solvent mixture, but is ample for thispurpose when thesolvent has a flash point no lower than that of methyl alcohol.

It has also been discovered that the addition of even as high as and more of mono-fluoro tri-chloro methane to flammable duplicating solvents such as ethyl and methyl alcohol or mixtures thereof will not appreciably influence their solvent characteristics, toward-s duplicating dyes.

To more clearly set forth the practice in accordance with this invention and to more specifically point out the nature of the composition contemplated thereby, the following example is given, it being understood that this example illustrates one embodiment which has given satis- -water and 5% of ethylene glycol mono-ethyl.

copies as the duplication liquid before the addition' of the mono-fluoro tri -chloro methane.

While the invention is particularly adaptable for the production of solvents used in direct process duplication, it is not'intended to restrict it to any particular use. The invention is of advantage in various manufacturing operations involving highly inflammable inorganic solvents, such as, for example, petroleum refining, manufacture of soya bean oil by the extraction method, manufacture of essential oils and the so- -called flower concretes by solvent extraction methods.

Although it is not intended to limit the invention to any theory, it is believed that the high efliciency of mono-fluoro tri-chloro methane as a flame reducing agent isdue to the fact that its boiling point is sufliciently low as to cause the formation of a non-flammable vapor. film on the surface of the organic solvent, with sufliciently high boiling point as to be substantially retained by the solvents even at high summer temperatures.

I claim: e

1. In admixture with a flammable solvent comprising a lower aliphatic alcohol adapted for use in moistening master copies in direct process duplication, from 3% to 35% of mono-fluoro tri-chloro methane as aflammability reducing agent.

2. A non-flammable solvent for use in moistening master copies in direct process duplication, composed mainly of a mixture of methyl and ethyl alcohols and having incorporated therein from 3% to 35% of mono-fluoro tri-chloro methane.

3. A non-flammable solvent for use in moistening master copies in direct process duplication, composed mainly of a mixture of methyl and ethyl alcohols and having incorporated therein approximately 10% of mono-fluoro tri-chloromethane. j

4. In the process rect duplication, in which a copy sheet is contacted with a design on a master sheet, the step of moistening the master sheet. with a solvent comprising monofluorotrichloromethane and a flammable alcohol which is a solvent for the dye of the design of the master sheet, the monofluorotrichloromethane being present in from 3% to 35% of the solvent mixture.

, JOHAN BJOltKSTEN'.

of producing copies by di-' 

